wait for initialize to complete before finalize

Signed-off-by: Brian Fletcher <brian@roadie.io>

.changeset/gorgeous-hairs-applaud.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-search-backend-node': patch
+---
+
+Wait for indexer initialization before finalizing indexing.

plugins/search-backend-node/src/indexing/BatchSearchEngineIndexer.ts

@@ -110,6 +110,11 @@ export abstract class BatchSearchEngineIndexer extends Writable {
    * @internal
    */
   async _final(done: (error?: Error | null) => void) {
+    const maybeError = await this.initialized;
+    if (maybeError) {
+      done(maybeError);
+      return;
+    }
     try {
       // Index any remaining documents.
       if (this.currentBatch.length) {